DESCRIPTION (adapted form the investigator's abstract): This project proposes to evaluate psychological well-being, symptom expression, and endocrine/immune functioning in women with two musculoskeletal conditions, fibromyalgia (FMS), and rheumatoid arthritis (RA). Specifically, the studies will assess whether a capacity to sustain a sense of psychological wellbeing results in severity and self-reported experience of symptoms. The first study will compare women with FMS, RA, and healthy controls across two phases of the menstrual cycle for symptom expression, pain sensitivity, and physiological function. In a second intervention study, an attempt will be made to enhance psychological wellbeing and positive affect with an eight-week training program in women newly diagnosed with RA and FMS.